This helped us get to the bottom of the problem, but it would have been better if we could have directly done a trace on the client machine to monitor the outgoing messages.

I had used Fiddler for something like this many years ago, but before I threw that into the mix I figured I would check if the WCF tools could be used on the client side.

And they can! 🙂

You simply need to run SvcConfigEditor.exe on the client application’s app.config file and set it up for message logging and / or tracing. Now after you restart your client app you can run SvcTraceViewer.exe and see the WCF service calls being made from it.